Biomedical subjects

Andrew S Yoo

Publications and source records attributed to Andrew S Yoo.

3 recordsLinked to original sources

PubMed2005

LIN-12/Notch activation leads to microRNA-mediated down-regulation of Vav in C. elegans.

Cell-cell interactions and cross-talk between signaling pathways specify Caenorhabditis elegans vulval precursor cells (VPCs) to adopt a spatial pattern: a central "1 degrees " VPC, in which epidermal growth factor receptor (EGFR)-mitogen-activated protein kinase (MAPK) activity is high and LIN-12/Notch activity is low, flanked by two "2 degrees " VPCs, in which LIN-12/Notch activity is high and EGFR-MAPK activity is low. Here, we identify a microRNA gene, mir-61, as a direct transcriptional target of LIN-12 and show that expression of mir-61 promotes the 2 degrees fate. We also identify vav-1, the ortholog of the Vav oncogene, as a target of mir-61, and show that down-regulation of VAV-1 promotes lin-12 activity in specifying the 2 degrees fate. Our results suggest that lin-12, mir-61, and vav-1 form a feedback loop that helps maximize lin-12 activity in the presumptive 2 degrees VPCs.

3' Untranslated Regions↗

PubMed2004

Cluster Analyzer for Transcription Sites (CATS): a C++-based program for identifying clustered transcription factor binding sites.

SUMMARY: We have developed a program, Cluster Analyzer for Transcription Sites (CATS), which identifies clusters of transcription factor binding sites in any genome sequence. The program searches for clusters of the consensus sequence for DNA binding within a window (length of DNA). The window size and the cluster size (number of consensus sequences within a given window) can be varied. CATS can be used for single or multiple transcription factors for which consensus sequences have been deduced based on biochemical and mutational analysis, or by comparative genomics. The use of CATS for clusters of different transcription factor binding sites may facilitate the identification of genes that are co-regulated in a cell type-specific or developmental stage-specific manner. CATS is simple to install and use on computers running any Windows NT-platforms. AVAILABILITY: http://www.healthsciences.columbia.edu/dept/greenwaldlab/links.html

Binding Sites↗

PubMed2004

Crosstalk between the EGFR and LIN-12/Notch pathways in C. elegans vulval development.

The Caenorhabditis elegans vulva is an important paradigm for cell-cell interactions in animal development. The fates of six vulval precursor cells are patterned through the action of the epidermal growth factor receptor-mitogen-activated protein kinase (EGFR-MAPK) inductive signaling pathway, which specifies the 1 degrees fate, and the LIN-12/Notch lateral signaling pathway, which specifies the 2 degrees fate. Here, we provide evidence that the inductive signal is spatially graded and initially activates the EGFR-MAPK pathway in the prospective 2 degrees cells. Subsequently, this effect is counteracted by the expression of multiple new negative regulators of the EGFR-MAPK pathway, under direct transcriptional control of the LIN-12-mediated lateral signal.

Animals↗